Comparative study of objective visual quality between FS-LASIK and SMART in myopia

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• Myopia correction is a common ophthalmic procedure.
• Transepithelial photorefractive keratectomy (SMART) and femtosecond laser in situ keratomileusis (FS-LASIK) are advanced refractive surgery techniques.
• Objective visual quality assessment is crucial for evaluating surgical outcomes.

Purpose of the Study:

• To compare objective visual quality changes after SMART PRK versus FS-LASIK in low to moderate myopia.
• To evaluate the impact of these procedures on corneal higher-order aberrations (HOAs) and optical quality metrics.

Main Methods:

• Corneal HOAs, coma, and spherical aberration were measured using Pentacam.
• Optical quality analysis system (OQAS-II) assessed modulation transfer function cutoff, objective scatter index (OSI), and Strehl ratio (SR).
• Measurements were taken preoperatively and at 1, 3, and 6 months postoperatively, with data analyzed using repeated measures ANOVA.

Main Results:

• Both groups showed increased HOAs postoperatively.
• Corneal vertical coma was higher in the FS-LASIK group compared to the SMART group.
• Objective scatter index (OSI) was elevated in both groups at 1 month, with slightly higher values in the FS-LASIK group at 3 and 6 months.
• Modulation transfer function (MTF) cutoff differed significantly between groups at 6 months.

Conclusions:

• Both SMART PRK and FS-LASIK lead to increased HOAs and delayed visual quality recovery.
• Long-term objective visual quality appears slightly better with SMART PRK compared to FS-LASIK.
• Further research may elucidate long-term differences in visual outcomes between these techniques.